19-2609; Rev 1; 12/02 MAX1470 Evaluation Kit The MAX1470 evaluation kit (EV kit) allows for a detailed evaluation of the MAX1470 superheterodyne receiver. It enables testing of the device’s RF performance and requires no additional support circuitry. The RF input uses a 50Ω matching network and an SMA connector for convenient connection to test equipment. The EV kit can also directly interface to the user’s embedded design for easy data decoding. The MAX1470 EV kit comes in two versions: a 315MHz version and a 433.92MHz version. The passive components are optimized for these frequencies. These components can easily be changed to work at RF frequencies from 250MHz to 500MHz. In addition, the 5kbps data rate can be adjusted from 0kbps to 100kbps by changing two more components. For easy implementation into the customer’s design, the MAX1470 EV kit also features a proven PC board layout, which can be easily duplicated for quicker time to market. The EV kit Gerber files are available for download at www.maxim-ic.com. Features ♦ Proven PC Board Layout (Compact 3cm ✕ 3cm) ♦ Proven Components Parts List ♦ Multiple Test Points Provided On-Board ♦ Available in 315MHz or 433.92MHz Optimized Versions ♦ 250MHz to 500MHz* Adjustable Frequency Range ♦ Fully Assembled and Tested ♦ Can Operate as a Stand-Alone Receiver with Addition of an Antenna *Requires component changes. Ordering Information PART TEMP RANGE IC PACKAGE MAX1470EVKIT-315 -40°C to +85°C 28 TSSOP MAX1470EVKIT-433 -40°C to +85°C 28 TSSOP Component List DESIGNATION QTY DESCRIPTION C1, C2, C12 3 0.01µF ±10% ceramic capacitors (0603) Murata GRM188R71H103KA01 C3 1 1500pF ±10%, 50V X7R ceramic capacitor (0603) Murata GRM188R71H152KA01 C4 C5 C6, C10 C7, C8, C11 C9 (315MHz) 1 0.47µF +80% - 20% ceramic capacitor (0603) Murata GRM188F51C474ZA01 DESIGNATION QTY DESCRIPTION C9 (433MHz) 1 3.0pF ±0.1pF ceramic capacitor (0603) Murata GRM1885C1H3R0BD01 C13, C16, C18, C19 0 Not installed C14, C15 2 15pF ±5%, 50V ceramic capacitors (0603) Murata GRM1885C1H150JZ01 470pF ±5% ceramic capacitor (0603) Murata GRM1885C1H471JA01 C17 0 1 0.1µF +80% - 20% ceramic capacitor (0603) Murata GRM188R71H103KA01, not installed F_IN 1 2 220pF ±5% ceramic capacitors (0603) Murata GRM1885C1H221JA01 SMA connector edge mount, not installed EFJohnson 142-0701-801 JU1 1 3 100pF ±5% ceramic capacitors (0603) Murata GRM1885C1H101JA01 3-pin header Digi-Key S1012-36-ND or equivalent — 1 Shunt (JU1) Digi-Key S9000-ND or equivalent 1 4.7pF ±0.1pF ceramic capacitor (0603) Murata GRM1885C1H4R7BZ01 JU3, JU4 0 Not installed ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 Evaluates: MAX1470 General Description Evaluates: MAX1470 MAX1470 Evaluation Kit Component List (continued) DESIGNATION QTY DESCRIPTION L1 (315MHz) 1 27nH ±5% inductor (0603) Murata LQG18HN27NJ00 L1 (433MHz) 1 15nH ±5% inductor (0603) Murata LQG18HN15NJ00 1 120nH ±5% inductor (0603) Toko LL1608FSR12J or Murata LQW18ANR12J00 L2 (315MHz) L2 (433MHz) 1 68nH ±5% inductor (0603) Toko LL1608FH68J or Murata LQG18HN68NJ00 1 15nH ±5% inductor (0603) Murata LQG18HN15NJ00 R1 1 5kΩ resistor (0603) Any supplier R2, R4 0 Resistor (0603), not installed R3 0 270Ω resistor (0603), not installed Any supplier R5 1 10kΩ resistor (0603) Any supplier RF_IN 1 SMA connector top mount EFJohnson 142-0701-201 L3 Component Suppliers SUPPLIER Crystek QTY DESCRIPTION MIX_OUT 0 SMA connector top mount, not installed EFJohnson 142-0701-201 TP1, TP2, TP4–TP8 0 Not installed 3.3V, GND, SHDN, DATA_OUT, TP3 5 Test points Mouser 151-203 or equivalent 1 Crystal 4.754687MHz Hong Kong Crystals SSL4754687E03FAFZ8A0 or Crystek 016867 Y1 (433MHz) 1 Crystal 6.6128 MHz Hong Kong Crystals SSL6612813E03FAFZ8A0 or Crystek 016868 Y2 1 10.7MHz ceramic filter Murata SFTLA10M7FA00-B0 U1 1 MAX1470EUI — 1 MAX1470 EV kit PC board Y1 (315MHz) • Optional ammeter for measuring supply current • Oscilloscope PHONE FAX 800-237-3061 941-561-1025 Connections and Setup This section provides a step-by-step guide to operating the EV kit and testing the device’s functionality. Do not turn on the DC power or RF signal generator until all connections are made: 1) Connect a DC supply set to 3.3V (through an ammeter, if desired) to the 3.3V and GND terminals on the EV kit. Do not turn on the supply. Hong Kong Crystals 852-2412-0121 852-2498-5908 Murata 800-831-9172 814-238-0490 Toko 408-432-8281 408-943-9790 Note: Please indicate that you are using the MAX1470 when contacting these component suppliers. Quick Start The following procedure allows for proper device evaluation. Required Test Equipment • Regulated power supply capable of providing 3.3V • RF signal generator capable of delivering from -120dBm to 0dBm of output power at the operating frequency, in addition to AM or pulse-modulation capabilities (Agilent E4420B or equivalent) 2 DESIGNATION 2) Connect the RF signal generator to the RF_IN SMA connector. Do not turn on the generator output. Set the generator for an output frequency of 315MHz (or 433.92MHz) at a power level of -100dBm. Set the modulation of the generator to provide a 2kHz, 100% AM-modulated square wave (or a 2kHz pulse-modulated signal). 3) Connect the oscilloscope to test point TP3. _______________________________________________________________________________________ MAX1470 Evaluation Kit 5) Activate the RF generator’s output without modulation. The scope should display a DC voltage that varies from approximately 1.2V to 2.0V as the RF generator amplitude is changed from -115dBm to -50dBm. 6) Set the RF generator to -100dBm. Activate the RF generator’s modulation and set the scope’s coupling to AC. The scope now displays a lowpass-filtered square wave at TP3 (filtered analog baseband data). Use the RF generator’s LF OUTPUT (modulation output) to trigger the oscilloscope. 3) Use capacitors C5 and C6 to set the corner frequency of the 2nd-order lowpass Sallen-Key data filter. The current values were selected for a corner frequency of 5kHz. Adjusting these values accommodates higher data rates (refer to the MAX1470 data sheet for more details). Layout Issues 2) With the above settings, a 315MHz-tuned EV kit should display a sensitivity of about -118dBm (1% BER), while a 433.92MHz kit displays a sensitivity of about -114dBm (1% BER). Note: The above sensitivity values are given in terms of average carrier power. If true pulse modulation is used instead of AM, then the sensitivity measurement is in terms of peak power, and as a result is reduced by 6dB. A properly designed PC board is an essential part of any RF/microwave circuit. On high-frequency inputs and outputs, use controlled-impedance lines and keep them as short as possible to minimize losses and radiation. At high frequencies, trace lengths that are approximately 1/20 the wavelength or longer become antennas. For example, a 2in trace at 315MHz can act as an antenna. Keeping the traces short also reduces parasitic inductance. Generally, 1in of a PC board trace adds about 20nH of parasitic inductance. The parasitic inductance can have a dramatic effect on the effective inductance. For example, a 0.5in trace connecting a 100nH inductor adds an extra 10nH of inductance, or 10%. To reduce the parasitic inductance, use wider traces and a solid ground or power plane below the signal traces. Using a solid ground plane can reduce the parasitic inductance from approximately 20nH/in to 7nH/in. Also, use low-inductance connections to ground on all GND pins, and place decoupling capacitors close to all VDD connections. The EV kit PC board can serve as a reference design for laying out a board using the MAX1470. All required components have been enclosed in a 1.25in x 1.25in square, which can be directly “inserted” in the application circuit. Table 1. Jumper Function Table Table 2. Test Points 7) Monitor the DATA_OUT terminal and verify the presence of a 2kHz square wave. Additional Evaluation 1) With the modulation still set to AM, observe the effect of reducing the RF generator’s amplitude on the DATA_OUT terminal output. The error in this sliced digital signal increases with reduced RF signal level. The sensitivity is usually defined as the point at which the error in interpreting the data (by the following embedded circuitry) increases beyond a set limit (BER test). JUMPER STATE JU1 1-2 Normal operation JU1 2-3 Power-down mode JU1 N.C. JU3 1-2 FUNCTION TP DESCRIPTION 1 PLL control voltage (Note: Connecting anything to this test point degrades RF performance.) External power-down control 2 Data slicer negative input 3 Data slicer positive input Mixer output to MIX_OUT 4 Peak detector out 5 VDD JU3 2-3 External IF input 6 GND JU3 N.C. Normal operation 7 Data filter feedback node JU4 1-2 Uses PDOUT for faster receiver startup 8 Data out 9 Power-down select input JU4 2-3 GND connection for peak detector filter _______________________________________________________________________________________ 3 Evaluates: MAX1470 4) Turn on the DC supply. The supply current should read approximately 6mA. Evaluates: MAX1470 MAX1470 Evaluation Kit Detailed Description Power-Down Control The MAX1470 can be controlled externally using the SHDN connector. The IC draws approximately 1.25µA in shutdown mode. Jumper JU1 is used to control this mode. The shunt can be placed between pins 2 and 3 for continuous shutdown, or pins 1 and 2 for continuous operation. Remove the JU1 shunt for external control. See Table 1 for the jumper function descriptions. IF Input/Output The 10.7MHz IF can be monitored with the help of a spectrum analyzer using the MIX_OUT SMA (not provided). Remove the ceramic filter for such a measurement and include R3 (270Ω) and C17 (0.01µF) to match the 330Ω mixer output with the 50Ω spectrum analyzer. Jumper JU3 needs to connect pins 1 and 2. It is also possible to use the MIX_OUT SMA to inject an external IF as a means of evaluating the baseband data slicing section. Jumper JU3 needs to connect pins 2 and 3. F_IN External Frequency Input For applications where the correct frequency crystal is not available, it is possible to directly inject an external frequency through the F_IN SMA (not provided). Connect the SMA to a function generator. The addition of C18 and C19 is necessary (use 0.01µF capacitors). Test Points and I/O Connections Additional test points and I/O connectors are provided to monitor the various baseband signals and for external connections. See Tables 2 and 3. Figure 1. MAX1470 EV Kit Table 3. I/O Connectors SIGNAL RF_IN F_IN MIX_OUT RF input External reference frequency input IF input/output GND Ground 3.3V 3.3V power input DATA_OUT SHDN 4 DESCRIPTION Sliced data output External power-down control _______________________________________________________________________________________ MAX1470 Evaluation Kit C15 15pF Y1 * C19 OPEN F_IN C16 OPEN 3.3V C18 OPEN 1 3.3V 2 TP5 C7 100pF XTAL2 XTAL1 PWRDN 3.3V RF_IN AVDD PDOUT 28 27 26 L2 * 3 5 6 N.C. LNASRC DF U1 LNAOUT OPP 3.3V DATA_OUT C9 * 22 TP7 21 C6 220pF 9 C10 220pF 10 GND 11 TP6 12 13 * 315MHz 433.92MHz C9 4.7pF 3.0pF L1 27nH 15nH 120nH 68nH L2 Y1 4.754687MHz 6.6128MHz 3.3V 14 20 TP2 MIXIN1 DSP MIXIN2 IFIN2 C5 470pF 19 TP3 18 AGND C3 1500pF N.C. 17 IFIN1 16 N.C. MIXOUT DGND DVDD C1 0.01µF C4 0.47µF R1 5kΩ C8 100pF 3.3V TP8 DSN DSN 8 JU4 R5 10kΩ AVDD C2 0.01µF C11 100pF TP9 24 MAX1470 7 3 3 25 N.C. 23 AGND 2 SHDN 1 2 DATAOUT 4 1 DSN C13 OPEN R2 OPEN LNAIN JU1 TP4 C12 0.01µF L3 15nH L1 * Evaluates: MAX1470 C14 15pF N.C. 15 3 TP1 1 IN GND Y2 OUT 10.7MHz 1 2 3 JU3 R3 OPEN C17 OPEN MIX_OUT 2 R4 OPEN Figure 2. MAX1470 EV Kit Circuit Diagram _______________________________________________________________________________________ 5 Evaluates: MAX1470 MAX1470 Evaluation Kit Figure 3. MAX1470 EV Kit Component Placement Guide—Top Silkscreen Figure 4. MAX1470 EV Kit PC Board Layout—Top Copper Figure 5. MAX1470 EV Kit PC Board Layout —Bottom Copper Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 6 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2002 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.